memory: Add shared pointer reinterpretPointerCast function (#47)

* memory: Add force reinterpret constructor to shared pointer

* memory: Change constructor to reinterpretPointerCast function

* memory: Add reinterpretPointerCast test

Author: PlasmaPower

include/hyprutils/memory/SharedPtr.hpp

@@ -144,7 +144,7 @@ namespace Hyprutils {
             Impl_::impl_base* impl_ = nullptr;
 
           private:
-            /* 
+            /*
                 no-op if there is no impl_
                 may delete the stored object if ref == 0
                 may delete and reset impl_ if ref == 0 and weak == 0
@@ -167,7 +167,7 @@ namespace Hyprutils {
                 impl_->inc();
             }
 
-            /* destroy the pointed-to object 
+            /* destroy the pointed-to object
                if able, will also destroy impl */
             void destroyImpl() {
                 // destroy the impl contents
@@ -185,6 +185,11 @@ namespace Hyprutils {
         static CSharedPointer<U> makeShared(Args&&... args) {
             return CSharedPointer<U>(new U(std::forward<Args>(args)...));
         }
+
+        template <typename T, typename U>
+        CSharedPointer<T> reinterpretPointerCast(const CSharedPointer<U>& ref) {
+            return CSharedPointer<T>(ref.impl_);
+        }
     }
 }
 

tests/memory.cpp

@@ -11,7 +11,7 @@ using namespace Hyprutils::Memory;
 
 int main(int argc, char** argv, char** envp) {
     SP<int> intPtr    = makeShared<int>(10);
-    SP<int> intPtr2   = makeShared<int>(1337);
+    SP<int> intPtr2   = makeShared<int>(-1337);
     UP<int> intUnique = makeUnique<int>(420);
 
     int     ret = 0;
@@ -52,5 +52,15 @@ int main(int argc, char** argv, char** envp) {
     EXPECT(weak.expired(), true);
     EXPECT(weakUnique.expired(), true);
 
+    auto intPtr2AsUint = reinterpretPointerCast<unsigned int>(intPtr2);
+    EXPECT(intPtr2.strongRef(), 4);
+    EXPECT(intPtr2AsUint.strongRef(), 4);
+
+    EXPECT(*intPtr2AsUint > 0, true);
+    EXPECT(*intPtr2AsUint, (unsigned int)(int)-1337);
+    *intPtr2AsUint = 10;
+    EXPECT(*intPtr2AsUint, 10);
+    EXPECT(*intPtr2, 10);
+
     return ret;
 }